Quaternary ammonium salts of higher alpha-sulfo fatty acids



E it

as mantr s .rarented Sept. 20, 1966" The object of the present invention is the preparation of microbiologically active compounds by reaction of certain quaternary ammonium hydroxides or their salts of inorganic acids with higher alpha-sulfo fatty acids or their monocarboxylic acid esters in the form of either the free acids or their water-soluble salts.

The products of this invention conform, in general, to the following structure:

wherein R is a straight or branched chain alkyl radical containing from 6 to 20 carbon atoms. Either X or Z, or both X and Z are the cations of a microbiologically active quaternary ammonium compound. When only one quaternary ammonium cation is present as X or Z, the remaining Z or X is either hydrogen or a metal cation, or an equivalent such as an ammonium or triethanol ammonium cation. WhenX is the cation of a microbiological1yactive quaternary ammonium compound, Z may, if desired, be an alkyl radical containing from 1 20 carbon atoms.

The alpha-sulfa fatty acids containing from 8 to 22 carbon atoms, as shown above, are well known to the art and may be prepared by any desired process such, for example, as direct sulfonation of a fatty acid with sulfur trioxide or with chlorsulfonic acid, or by reaction of an alpha-chloro fatty acid salt or alpha-bromo fatty acid salt with an alkali metal sulfite or ammonium sulfite. Typical alpha s,'ulfo fatty acids which may be used for the purposes of this invention include alpha-sulfo-decanoic acid, alpha-sulfo-octanoic acid, alpha-sulfo-lauric acid, alpha-sulfo-myristic acid, alpha-sulfo-palmitic acid, alphasulfo-stearic acid, alpha-sulfo-arachidic acid, alpha-sulfobehenic acid, and the corresponding branched chain acids containing from 8 to 22 carbon atoms and having a sulfonic acid radical attached to the carbon atom adjacent to the carboxyl group.

Instead of the alpha-sulfo acids just enumerated, any of their carboxylic acid esters in which the hydrogen of the carboxyl group is replaced by an alkyl radical containing from 1 to 20 carbon atoms, such as methyl, ethyl, propyl, lauryl, palmityl, myristyl, stearyl, arachidyl or the like, may be employed.

Both the alpha-sulfa acids and their monocarboxylic acid esters may be employed in the reaction of this invention in the form of the free acids or their water-soluble salts.

Typical examples of the quaternary ammonium compounds which may be used in this invention are the alkyl trimethyl ammonium chlorides, alkyl-benzyl trimethyl ammonium chlorides, alkyl dimethyl benzyl ammonium chlorides, alkyl dimethyl menaphthyl ammonium chlorides, alkyl dimethyl substituted-benzyl ammonium chlorides in which the benzyl radical is substituted with one or more side chains containing from 1 to 5 carbon atoms such, for example, as methyl, dimethyl, ethyl and the like and in which the carbon atoms may all be in the same or diiferent side chains or in which the benzyl radical bears one, two or more halogen atoms such as chlorine or bromine, alkyl pyridinium chlorides, alkyl isoquinolinium chlorides and bromides, alkyl lower-alkyl pyrrolidinium chlorides, alkyl lower-alkyl morpholinium chlorides in all of which the alkyl group may have from 8 to 22 carbon atoms and the lower alkyl group may have from l to 4 carbon atoms and alkyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride in which the alkyl radical may be iso-octyl or nonyl and in which the phenyl radical may, if desired, be substituted by a methyl radical. Various other analogs of these quaternaries may also be employed such, for example, as cetyl dimethyl ethyl ammonium bromide or oleyl dimethyl ethyl ammonium bromide.

In general, the quaternary ammonium compounds useful in this invention are the higher alkyl quaternary ammonium hydroxides, halides (chlorides and bromides), sulfates, methosulfates and the like possessing the following formula:

radical in which R is an alkyl radical containing from 8 to 9 carbon atoms and in which the phenyl radical may be substituted by a methyl group; R and R" are methyl or ethyl radicals or members of a heterocyclic ring sys-' tem such as pyridine, isoquinoline, pyrrolidine and more pholine; R is a methyl radical or a benzyl group or a substituted-benzyl group such, forexample, as a monochlorobenzyl radical or a dichlorobenzyl radical or mixture thereof or a methyl benzyl, dimethyl benzyl, ethyl.

benzyl, diethyl benzyl, isopropyl benzyl, tertiary butyl benzyl or another benzyl radical containing from 1 to 5 carbon atoms as side chains, either as a single side chain or a multiplicity of side chains including mixtures thereof or a menaphthyl group or hydrogenated menaphthyl group. When R and R" are members of a morpholine or pyrrolidine ring, R' is a methyl, ethyl, propyl, or butyl group. When R and R" are members of an unsaturated heterocyclic ring such as pyridine or isoquinoline, R' is the same radical as R". X in the above formula corresponds to a halide radical such as chloride, bromide or iodide or to any other water-soluble anion such as methosulfate.

In general, we prefer to use such quaternary ammonium compounds which have a phenol coeificient of at least with respect to both Staphylococcus aureus and Salmonella typhosa at 20 C. when determined by the standard method given in the Ofiicial Methods of Analysis of the Association of Official Agricultural Chemists, ninth edition (l960), page 63 et seq.

The compounds of this invention may be prepared by mixing aqueous solutions of the quaternary ammonium salts or hydroxides with an aqueous solution of the acid in question or any of its water-soluble salts.

After thorough mixing, the organic product layer is separated from the aqueous layer (as with a separatory funnel) since two distinct phases are formed. Separation may be facilitated by the addition of an organic solvent immiscible with water. The product layer may be washed with water to remove any residual by-product salt or unreacted materials. The solvent, if any, may be evaporated and the product air or vacuum dried to a paste, wax, oil or solid.

It is not necessary to use an aqueous medium. Any solvent or solvent mixture in which the starting materials are soluble will be satisfactory. Non-aqueous solvents facilitate the separation of by-product inorganic salt and reduce the need for vacuum drying to get an anhydrous product. When a non-aqueous medium is employed, it is mars, ace

F usually n cessary to add a small amount of water to facilitate ionic reaction.

The product may be used, if desired, without drying since any entrapped water is irrelevant to the microbiological activity of the compounds. In other applications, removal of water may be essential for reasons not related to biological activity.

Au alternative method for the preparation of compounds especially applicable to the treatment of fabric, ropes, net, woven and nonwoven fabric and reticulated or convoluted materials, involves a two-step process. In the first step, the material is passed through a bath containing the anionic moiety. Excess solution is removed by methods well known to those skilled in the art. The treated material is then passed through a second bath wherein the concentration of quaternary ammonium compound is such that the material pickup will result in an equivalent amount of quaternary ammonium compound reacting with the anionic moiety, depositing the product in the most intimate way on the surface and in the interstices, convolutions and reticulations of the material.

The method of adjustment of solution concentration to achieve the required pickup is well known to those skilled in the art. The order of treatment may be reversed with out affecting the biological activity or durability of the product on the material. The products of this invention may be formulated as water dispersions by dissolving them in a water miscible organic solvent such as acetone or methanol and diluting with water or by dissolving them in emulsifiable oils such, for example, as sulfonated castor oil or pine oil and diluting with water. In preparing aqueous dispersions, emulsifying agents such, for example, as ethylene oxide condensates of alkyl phenols may be used with or without organic solvents.

It is surprising that the compounds of this invention exhibit high microbiological activity despite their relative insolubility in water. I Because of their unusual combination of physical and microbiological properties, they can be used to impart laundry-resistant anti-microbial characteristics to textiles. They can also be used as the active agent in antimildew finishes for textiles which are resistant to leaching with water.

Although the compounds have low water solubility, they are compatible with various organic solvents, plasticizers and high molecular weight compounds. Consequently, they may be incorporated as anti-microbial agents in synthetic resins and plastics. The compounds are compatible with natural and synthetic rubber latices. Therefore, they may be used to prepare bacteriostatic films and molded objects deposited from such latices.

The compounds can be incorporated into cut-ting and grinding fluids Without precipitation. Also, they blend well with non-ionic and anionic surface active agents. In such compositions they retain their microbiological activity.

It will be understood that the properties of the products described herein will vary depending upon the nature of the cationic quaternary ammonium compound used in their preparation as well as the anionic compound reacted therewith.

The chemical, physical and biological properties of the products of our invention make them especially appropriate for the following applications when suitably incorporated in active amounts in an appropriate vehicle, binder, medium or substrate:

(1) Mildewproofing fabric, canvas, ropes, textiles, awnings, sails, tenting and other woven and non-woven reticulated materials.

(2) Paint mildewstats.

(3) Jet plane fuel additive to control growth of microorganisms.

(4) Odor preservative agents for clothes and shoes.

(5) Mildew retardant and odor suppressant for shoes and other leather products.

(6) Topical antiseptics.

(7) Antidandrutf agents.

(8) Disinfection agents for hair and gut of man and beast.

(9) Bacteriostatic furniture dressing.

(10) Surface finishes for stone, plaster, tile, cement, brick and other inorganic building materials, to retard growth of microorganisms, fungi, mold and algae.

(ll) Wool preservative.

(12) Plant and tree spray to combat fungi.

(l3) Antimycotic agents for soap wrappers.

(l4) Self-sanitizing brushes.

(15) Mildewproofing agent in and on plastic arid film.

(l6) Mildewproofing of cellulosics, cardboard, fibreboard, paper and cordage.

(17) Contact biostate for application to film, waxes and cloth to preserve cheese, meats and vegetables and other food products.

( l8) Algal inhibition, especially on surfaces and in solution where low foaming is desirable.

(19) Paper pulp slime control.

(20) Sanitizing agent for rug, carpeting, curtains.

(21) Egg preservation.

(22) Adhesive preservation.

(23) Preservation of latex paints.

(24) Preservation of metal-working compounds.

(25) Additives for soap and for both anionic and nonionic detergents in liquid, bar, powder, bead, solution and other forms to impart bacteriostatic and fungistatic properties thereto.

The microbiological activity of our compounds has been evaluated for microbiological stasis by the Standard Tube Dilution Test, the technique for which is common knowledge to those skilled in the art. A Difco Bacto CSMA broth #0826 was used in the study. This test is used to determine the lowest concentration of microbiologically active compounds which will inhibit the growth of the organism in question. For a wide range of applications, the inhibition of growth rather than outright kill is satisfactory.

Briefly put, the Tube Dilution Test consists in placing 9 cc. of the CSMA broth in a test tube which is then sterilized in an autoclave. One cc. solution of the microbiologically active compound at an appropriate concentration is added to the test tube which is then inoculated with 0.1 cc. of a twenty-four hour old culture of the organism under study. The test tube is then incubated at 37 C. for forty-eight hours and observed for bacterial growth.

The same procedure is followed for fungi. In such tests, however, the tubes are incubated for fourteen days .at a temperature suitable for optimum fungal growth,

Example 1 Three liters of a 1% (by weight) solution of the disodium salt of alpha-sulfo-stearic acid were prepared in 50:50 isopropanol-water. One liter of this solution was added to 200 grams of a 10% aqueous solution of alkyl dimethyl ethyl-benzyl ammonium chloride (alkyl distribution: C 50%; C 30%; C 17%; C 3%; ETC-471," Onyx Chemical Corporation) in a two liter beaker. The beaker was heated on a steam bath to remove the isopropanol until two layers formed. These were separated in a separatory funnel. The product layer was dried in a vacuum oven to give di(alkyl dimethyl ethyl-benzyl ammonium) alpha-sulfo-stearate, a gray paste, in 99% yield.

Example II A second liter of the 1% solution of the disodium salt of alpha-sulfo-stearic acid described in Example I was mixed with 200 grams of a 10% aqueous solution of alkyl dimethyl benzyl ammonium chloride (alkyl distribution: C 60%; C 30%; C 5%; C 5%; ETC-824,

Onyx Chemical Corporation) in a two liter beaker. The product was worked up as described in Example I to give 28 grams (100% yield) of a gray paste, dit'alkyl dimethyl bcnzyl ammonium) alpha-sulfostearate.

Example Ill alents of quaternary ammonium halides in Examples I to III, the corresponding half-salts may be prepared by using only one equivalent of quaternary ammonium salt per mole of sulfo-stearic acid disodium salt.

Similar results to those shown above were obtained by replacing the alpha-sulfo-stearic acid with alpha-sulfolauric acid, alpha-sulfo-myristic acid, alpha-sulfopalmitic acid, alpha-sulfo-behenic acid, and the monomethyl carboxylate esters of alpha-sulfo-lauric and myristic acids.

Example IV Using the Standard Tube Dilution Test described above, the following bacteriostatic levels were determined (S.a.= Staphylococcus aureus; S.t.=Salmnella typliosla; A.n.= Aspergillus niger):

Bacterlostat-ic Dilution Level Level vs. Product From S.a. S.t. An.

Example I 105 105 10 Example II 105 105 104 Example III 104 104 Exam plc V The product from Example 11 was run against Desaljovibrlo desul/urimns according to the procedure outlined in the report by the American Petroleum Institute Subcommittee on Biological Analysis of Injection Waters to be Used for Water Flood Purposes (March 17, 1958). This product showed a bacteriostatic level of 7.5 p.p.m.

I claim:

1. Di(alky1 dimethyl cthyl-benzyl ammonium) alphasullo-stearate wherein the alkyl has 8 to 22 carbon atoms.

2. Di(alkyl dimethyl benzyl ammonium) alphasulfosulfo-stearate wherein the alkyl has 8 to 22 carbon atoms.

3. Di(1auryl isoquinolinium) alpha-sulfo-stearate.

4. The salt of an alkyl quaternary ammonium compound and an alpha-sulfo-fatty acid selected from the group consisting of a1pha-sulfo-decanoic acid, alpha-sulfooctanoic acid, alpha-sulfo-lauric acid, alpha-sulfo-myristic acid, alpha-sulfo-palmitic acid, alpha-sulfo-stearic acid, alpha-sulfo-arachidic acid, and alpha-sulfo-behenic acid said alkyl quaternary ammonium compound having a phenol coeflieient of at least with respect to both Staphylococcus aureus and Salmonella typhosa at 20 C. and having at least one alkyl having 8 to 22 carbon atoms.

References Cited by the Examiner UNITED STATES PATENTS 2,087,506 1/1937 de Groote 260-404 X 2,759,975 8/1956 Chiddix 360-326 X 3,070,600 12/1962 Rudner 260247.2

OTHER REFERENCES Schwartz et al.: Surface Active and Detergents, volume II Interscience, 1958, page 211 relied upon.

ALEX MAZEL, Primary Examiner.

HENRY R. JILES, Examiner.

DONALD D. DAUS, Assistant Examiner. 

3. DI(LAURYL ISOQUINOLINIUM) ALPHA-SULFO-STEARATE.
 4. THE SALT OF AN ALKYL QUATERNARY AMMONIUM COMPOUND AND AN ALPHA-SULFO-FATTY ACID SELECTED FROM THE GROUP CONSISTING OF ALPHA-SULFO-DECANOIC ACID, ALPHA-SULFOOCTANOIC ACID, ALPHA-SULFO-LAURIC ACID, ALPHA-SULFO-MYRISTIC ACID, ALPHA-SULFO-PALMITIC ACID, ALPHA-SULFO-STEARIC ACID, ALPHA-SULFO-ARACHIDIC ACID, AND ALPHA-SULFO-BEHENIC ACID SAID ALKYL QUATERNARY AMMONIUM COMPOUND HAVING A PHENOL COEFFICIENT OF AT LEAST 100 WITH RESPECT TO BOTH STAPHYLOCOCCUS AUREUS AND SALMONELLA TYPHOSA AT 20*C. AND HAVING AT LEAST ONE ALKYL HAVING 8 TO 22 CARBON ATOMS. 